289 results about "Ferric" patented technology

The invention relates to a special fertilizer suitable for saline-alkali soil and a preparation method thereof. The fertilizer is granular and has a multi-layer structure which is sequentially arranged from inside to outside: a nutrition core layer, a controlled release film layer, a soil improvement fast exchange layer and a microorganism attaching layer. The nutrition core layer contains nitrogen, phosphorus, potassium and medium trace elements, and meets the basic nutrient requirements of crops; the controlled release film layer is self-assembled layer by layer by adopting alginate / chitosan, a humic acid-ferrous complex and a breakable cross-linking point are inserted into the film, and starch is sprayed on the outer layer, so that an ionic strength / alkalinity dual-response controlled release system is formed; the soil improvement quick exchange layer contains microcrystalline gypsum and ferrous sulfate; the microbial epiphytic layer fixes salt-tolerant phosphate solubilizing bacteria, potassium bacteria and exopolysaccharide-producing bacillus by using a charcoal-zeolite carrier, and the bacteria are distributed on the surfaces of the particles in a dotted manner. The fertilizer realizes organic combination of soil improvement, fertilizer supply and microbial regulation and control, can significantly reduce the soil salinity and alkalinity in a saline-alkali soil environment, and improves the fertilizer utilization rate and the crop growth performance.

The invention belongs to the technical field of electrochemistry, and particularly provides a lanthanum-cerium double-doped sodium ferric sulfate positive electrode material and a preparation method thereof. The material is composed of a matrix and a carbon coating layer coating the matrix, the matrix has a chemical expression of Na6Fe4-x-yLaxCey (SO4) 7, x is greater than or equal to 0.01 and less than or equal to 0.1, and y is greater than or equal to 0.01 and less than or equal to 0.1. The material is prepared through spray drying and high-temperature sintering treatment in sequence, the particle morphology is regular, and the particle size distribution is uniform; the electronic conductivity and Na < + > diffusion rate of the material are remarkably improved by rare earth doping, so that the material has more excellent low-temperature cycle performance, sodium storage performance and the like.

The application provides an oilfield produced water treatment method. The method comprises the following steps: adding a polymeric aluminum ferric silicate solution into oilfield produced water to be treated, and stirring for a period of time at a first rotating speed; increasing the first rotating speed to a second rotating speed, adding a polyacrylamide solution, stirring for a period of time at the second rotating speed after the addition is completed, and then standing for a period of time; and filtering to obtain treated oilfield produced water. The method has the advantages of simplicity, high efficiency, low cost, easy operation, remarkable treatment effect and the like.

The invention belongs to the field of medicines, and discloses a preparation process of ferric carboxymaltose, which comprises the following steps: oxidizing maltodextrin, performing ultrafiltration concentration, dissolving in a ferric trichloride aqueous solution, and performing coordination, ultrafiltration and spray drying to obtain powdery ferric carboxymaltose. The process has the advantages of simple amplification, no need of solvent application, low raw material cost and manufacturing cost, uniform product molecular weight distribution and the like, the dissolution rate of the obtained product is obviously higher than that of a product obtained by a precipitation process, and technical support is provided for more efficient preparation production.

The invention provides sodium ferric pyrophosphate and a preparation method thereof, and the preparation method comprises the following steps: mixing waste sodium ferric pyrophosphate with carbonate and an iron source to obtain a mixture, and calcining the mixture to obtain a calcined material; washing and filtering the calcined material to obtain a first filter residue and a first filtrate; performing impurity removal, concentration and crystallization on the first filtrate to obtain sodium carbonate; the first filter residues are subjected to acid pickling and filtering treatment, and second filtrate is obtained; adding phosphate and a pH regulator into the second filtrate, and heating for reaction to obtain mixed slurry; filtering the mixed slurry to obtain second filter residues, and sequentially drying, screening and deironing the second filter residues to obtain iron hydrogen phosphate; the preparation method comprises the following steps: mixing sodium carbonate with ferric hydrogen phosphate, then adding a doping agent, an auxiliary agent and a carbon source, and grinding and calcining to obtain the ferric sodium pyrophosphate. According to the method, high-purity sodium carbonate and iron hydrogen phosphate can be recycled, then pyrophosphate ferric sodium phosphate is prepared, and the pyrophosphate ferric sodium phosphate is good in particle dispersity, high in sphericity degree and high in capacity.

The invention relates to the technical field of preparation of small molecule compound medicines, in particular to a preparation method of (S)-flurbiprofen. The method comprises the following steps: dropwise adding a tetrahydrofuran solution of 4-bromo-2-fluorobiphenyl into a mixture of tetrahydrofuran and magnesium, and reacting to generate a Grignard reagent; mixing tetrahydrofuran, (S)-vinyl chloride oxide and ferric acetylacetonate, dropwise adding the Grignard reagent, performing acidolysis ring opening, and performing methylation with methyl iodide and magnesium iodide to obtain an alpha-hydroxyl aromatic carboxylic acid derivative; and reacting with sodium chlorite, nitroxide free radicals and acetonitrile, and oxidizing to obtain the (S)-flurbiprofen. By introducing a chiral induction unit, effective transmission of chiral information is realized in a coupling stage, an original chiral center is not destroyed in a subsequent reaction, and a product is ensured to have a highly consistent configuration. According to the scheme, the technical problem that a method capable of remarkably improving the optical purity and yield of (S)-flurbiprofen is lacked in the prior art can be solved, and the method has good environmental friendliness and industrial application prospects.

The application discloses polymeric ferric chloride and a production process and application thereof, and preparation of the polymeric ferric chloride comprises the following steps: S1, mixing waste acid with iron oxide scale, adjusting acidity, heating and refluxing, and cooling to obtain a mixture; S2, adding an oxidizing agent and a stabilizer into the mixture, and continuously heating and reacting to obtain the polymeric ferric chloride; the stabilizer is a chitosan-desferrioxamine complex; the polymeric ferric chloride is prepared by using a catalytic oxidation method, the chitosan-desferrioxamine complex stabilizer is used to chelate Fe, the stability of the polymeric ferric chloride is improved, the hydrolysis of Fe is inhibited, and the process is beneficial to improving the total iron content in the polymeric ferric chloride and improving the flocculation effect of the polymeric ferric chloride in sewage treatment.

The application discloses a preparation method of polyaluminum chloride, and is characterized by comprising the following steps: S1, adding aluminum ash and hydrochloric acid solution into an acidification reaction tank, heating and reacting, filtering after the reaction is completed, and passing the filtrate into a polymerization reaction kettle; S2, adding calcium carbonate into the polymerization reaction kettle in batches to carry out polymerization reaction, stopping the reaction after the calcium carbonate is completely dissolved and the PH of the solution is 3-5; S3, adding polyacrylamide and ferric chloride into the polymerization reaction kettle, and precipitating under 1-3 pa low pressure to obtain sludge and upper liquid, concentrating and crystallizing the upper liquid, crushing the crystal, and obtaining polyaluminum chloride. The application increases an automatic blocking mechanism below a crystallization and crushing tank, automatically blocks when the sub-packaging cylinder is filled with crystals, achieves the purpose of quantitative sub-packaging, and does not cause too much or too little crystals in the sub-packaging cylinder, and does not require staff to be always beside the machine.

The invention relates to the field of biomedicine, and particularly provides bimetal MOFs with photo-thermal and anti-oxidation effects and a preparation method and application thereof.The preparation method comprises the following steps that 1, 4, 5, 8-naphthalene tetracarboxylic dianhydride and 4-amino-4H-1, 2, 4-triazole are dispersed in DMF, a reflux reaction is conducted at the temperature of 140-160 DEG C, and a DBPT organic ligand is obtained; the preparation method comprises the following steps: fully dissolving a DBPT organic ligand, anhydrous ferric chloride, anhydrous cupric nitrate and fluoboric acid in DMF at room temperature to obtain a reaction solution, carrying out ultrasonic treatment on the reaction solution, stirring until the reaction solution is completely dissolved, putting the obtained solution into a high-pressure reaction kettle, carrying out a heating reaction, and cooling to room temperature after the reaction is finished; and centrifuging the product, cleaning and drying to obtain the Fe / Cu-MOFs. The preparation method disclosed by the invention is simple to operate, and the prepared bimetallic MOFs have good photo-thermal and oxidation resistance and can be applied to multiple treatment requirements of bacterial infection and inflammation environment regulation and control.

The invention discloses a smelting process of high-iron high-lead zinc concentrate, and belongs to the technical field of comprehensive utilization of resources, and the method specifically comprises the following steps: carrying out normal-pressure leaching on the high-iron high-lead zinc concentrate and oxygen pressure leaching liquid to produce normal-pressure leaching residues and normal-pressure leaching liquid, and carrying out mineralization iron removal on the normal-pressure leaching liquid to produce iron concentrate; the normal-pressure leaching residues are subjected to traditional sulphide ore dressing, and high-lead residues and low-lead zinc concentrate are produced; the low-lead zinc concentrate and the zinc hydrometallurgy electrolyte are subjected to high-temperature oxygen pressure leaching, silver-sulfur concentrate and ferric-iron-containing high-acid oxygen pressure leaching liquid are produced, and the ferric-iron-containing high-acid oxygen pressure leaching liquid is returned to be used for normal-pressure leaching; directly hot-melting and filtering the silver-sulfur concentrate to produce sulfur and silver concentrate; according to the method, the normal-pressure leaching, mineral separation and oxygen pressure leaching combined process is adopted, the leaching process and the oxygen pressure leaching slag treatment process are simplified, high-lead slag, iron ore concentrate and silver-sulfur concentrate are directly produced in the smelting process instead of mixed slag with low content of lead, iron, sulfur and silver in a traditional oxygen pressure leaching process, the silver enrichment ratio in final leaching slag is high, and the sulfur recovery process is simple.

The application belongs to the technical field of food quality monitoring, and particularly relates to a ferric magnetic solid-phase masking agent and a quantitative detection method for lead in vegetable products. The ferric magnetic solid-phase masking agent is prepared by the following method: S1, performing carboxylation on the terminal amino group of DFO to obtain DFO-COOH; S2, coating a SiO2 layer on the surface of Fe3O4 magnetic core to obtain Fe3O4@SiO2; S3, modifying the Fe3O4@SiO2 by amination to obtain Fe3O4@SiO2-NH2; and S4, coupling Ac-DFO with Fe3O4@SiO2-NH2 to obtain Fe3O4@SiO2-DFO. The three hydroxamic acid groups of DFO are combined with Fe 3+ to form a stable chelate, and Fe 3+ can be removed through magnetic separation, the removal rate is increased to more than 99%, and the quantitative detection of lead ions is further faster and more accurate in combination with mature immunochromatography technology.

The invention provides a method for removing ferrous iron in a nickel chloride solution through efficient oxidation promotion, belongs to the technical field of purification treatment of chlorination system solutions, and solves the problem that free ferrous iron in the nickel chloride solution cannot be effectively oxidized and converted into ferric iron in the prior art. Controlling the concentration of main metal nickel ions, and adding a corresponding amount of hydrogen peroxide into the nickel chloride solution for stirring according to the content of impurity Fe in the nickel chloride solution; injecting the stirred nickel chloride solution into an electrolytic bath, heating, and raising the temperature of the nickel chloride solution in the bath; and the cathode and the anode in the electrolytic bath are conducted, and the introduced nickel chloride solution is subjected to electrolytic treatment, so that divalent iron in the nickel chloride solution can be converted into trivalent iron. The process flow is simple, the production process is easy to control, the facility equipment investment is low, and the final benefit is remarkable.

The invention discloses an SCR catalyst ammonium sulfate poisoning rapid recovery method, and relates to the technical field of industrial flue gas denitration, and the specific method comprises the following steps: S1, when it is detected that the denitration efficiency of an SCR system is lower than a threshold value, the temperature of flue gas entering an SCR reactor is controlled to be T1, and the temperature is maintained for t1; s2, a ferric nitrate solution is sprayed into flue gas at an inlet of the SCR system, and the temperature T2 is maintained for t2; and S3, the ferric nitrate solution is stopped from being added, the flue gas temperature is gradually reduced to the normal operation temperature, and normal operation of the SCR system is recovered. The ferric nitrate sprayed into the flue gas not only can introduce NO2 into the flue gas and quickly recover the valence state of the vanadium active center in the catalyst under a low-temperature condition, so that the efficient regeneration of the catalyst activity is realized, but also the formed metal oxide can achieve a synergistic promotion effect in the quick recovery process of ammonium sulfate poisoning of the SCR catalyst.

The present disclosure relates to a kind of ferric phosphate and its preparation method and use, the preparation method includes the following steps: (1) mixing ammonium ferrocyanide and phosphorus source, obtain iron-phosphorus mixed solution;(2) the iron-phosphorus mixed solution obtained in step (1) is carried out spray pyrolysis, obtain solid particles;(3) the solid particles obtained in step (2) are broken, obtain ferric phosphate.The ferric phosphate provided by the present disclosure has higher purity, tap density and specific surface area, the preparation method can avoid using pH regulator and surfactant, reduce by-product production and cleaning step, greatly simplify production process, have higher industrial application value.

The utility model relates to the technical field of material dissolving, in particular to a dissolving tank for producing polymeric ferric sulfate, which is capable of uniformly mixing materials. According to the technical scheme, the stirring device comprises a bottom plate, a base plate and a tank body, the tank body is arranged on the upper surface of the bottom plate, the base plate is arranged at an opening of the tank body in a lifting mode through a lifting assembly, a first-stage stirring assembly and a second-stage stirring assembly are arranged on the base plate, the first-stage stirring assembly is rotationally connected with the second-stage stirring assembly, and the second-stage stirring assembly is rotationally connected with the first-stage stirring assembly. The first-stage stirring assembly is located at the bottom of the tank body, and the second-stage stirring assembly is located in the middle of the tank body. According to the utility model, materials in different areas in the tank body can be effectively stirred at the same time through the matching of the structures, so that the overall material dissolving efficiency is improved, the working intensity of the motor can be adjusted according to actual requirements, and unnecessary energy consumption waste is avoided.

This invention discloses a magnetic Ni x％ This paper describes the preparation method and application of FeNb2O6 composite catalysts, which fall under the technical field of supported bimetallic oxide catalysts. First, magnetic FeNb2O6 nanocatalysts are prepared via a one-pot hydrothermal method using niobium oxalate hydrate as the niobium source and ferric nitrate as the iron source. Then, magnetic Ni is prepared via a modified deposition precipitation method using nickel nitrate as the nickel source and the magnetic FeNb2O6 nanocatalyst as the support. x％ @FeNb2O6 composite catalyst. The beneficial effect of this invention is that Ni... x％ In the FeNb2O6 composite catalyst, iron, niobium, and nickel species are highly dispersed with no obvious agglomeration, exhibiting high activity and high stability. Furthermore, the catalyst's magnetic properties allow for recovery and reuse, overcoming the shortcomings of traditional metal catalysts such as easy loss and difficulty in recovery after reaction. This Ni... x％ The FeNb2O6 composite catalyst is used for the catalytic hydrogenation conversion of Caragana korshinskii and its related model compounds. Due to its high C-O- bond cleavage activity, it can more effectively promote the depolymerization of Caragana korshinskii organic matter, thereby obtaining bio-oil rich in high-value COH functional groups.

The present invention discloses a controlled-release type polymeric ferric sulfate water treatment agent and its preparation method, belonging to the technical field of water treatment functional materials. The water treatment agent consists of polymeric ferric sulfate, an iron ion color indicator, a gel matrix, a cross-linking calcium agent, amino diatomaceous earth, a pore-forming agent and an inert filler. The preparation method includes: first preparing a network gel, then preparing soft materials, and finally obtaining the product through pill-making and drying. The present invention realizes the slow release and controllability of polymeric ferric sulfate, and the color indicator can directly reflect the consumption state of polymeric ferric sulfate, facilitating storage, transportation, dosing and recovery.

The invention relates to the technical field of desulfurizing agents, in particular to a reusable iron oxyhydroxide desulfurizing agent and a preparation method thereof. The problem that the activity of a traditional material is reduced due to sulfate accumulation and compact layer formation in a vulcanization-regeneration cycle is solved. The preparation method comprises the following steps: dissolving ferric nitrate and urea, adjusting the pH value to 1.8, and adding cerous nitrate and citric acid; heating, introducing zirconium oxynitrate, controlling the pH value at 3.7-3.9 for 2-3 hours, heating to 7.2, adding samarium nitrate and zirconium acetylacetonate, aging, and mixing with bentonite and ammonium bicarbonate for molding; and finally, carrying out segmented activation in a nitrogen and low-oxygen mixed atmosphere. The desulfurizer has high specific surface area and pore volume, the breakthrough sulfur capacity reaches 148-160mgS / g, the 10-time circulating sulfur capacity retention rate is 88-91%, and the desulfurizer is high in particle compressive strength, low in abrasion rate and suitable for the industrial desulfurization process.

The invention belongs to the technical field of catalyst carriers, and particularly relates to a preparation method of a high-strength catalyst carrier, which comprises the following steps: S1, preparing a precursor; the preparation method comprises the following steps: dissolving ferric nitrate-zirconium nitrate composite salt, 2, 5-dihydroxy terephthalic acid and a monatomic Fe source in N-methyl pyrrolidone according to the ratio of the total molar weight of metal ions to the volume of N-methyl pyrrolidone of 1mmol: 5.6 mL, and reacting at 150 DEG C to form monatomic Fe-doped Fe-Zr-MOFs seed crystal; adding a reaction monomer and a protonic acid catalyst into the system, and heating to 170 DEG C for reaction; centrifuging after cooling, and carrying out gradient elution treatment and vacuum drying to obtain a precursor; s2, putting the precursor obtained in the step S1 into a mixed atmosphere tube furnace, introducing 12 vol% H2 / N, raising the temperature to 550 DEG C at 7 DEG C / min, and keeping the temperature for 3 hours; then introducing 9vol% SiH / Ar, raising the temperature to 1000 DEG C at the speed of 10 DEG C / min, and keeping the temperature for 6 hours; and cooling to obtain the low-magnetization carbon heterogeneous matrix.

The present application relates to a kind of carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material and preparation method and application, with six hydrated ferric chloride as iron source, with chitin as nitrogen, carbon source. By simple one-step method, after mixing, calcination, grinding way, carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material is synthesized.The material prepared by the present application presents two-dimensional layered structure, after adding potassium hydrogen peroxodisulfate oxidant, the material can completely remove the active pharmaceutical ingredient naphthyl in water in a short time.Naproxen.The synthesis method proposed in the present application is simple and easy to operate, and the material performance is excellent, which can provide a new design idea for nitrogen coordination iron nanomaterial supported by carbon material, and be applied to the remediation of contaminated water.

The invention discloses a preparation method of a polyanion positive electrode material ferric sodium pyrophosphate (NFPP, chemical formula: Na4Fe3 (PO4) 2P2O7) without a physical sanding process, and relates to the technical field of synthesis of inorganic functional materials. According to the method, dependence of a traditional process on physical sanding is broken through, common industrial raw materials are adopted, an iron source is limited to be a mixed system of water-insoluble iron phosphate and ferrous oxalate (the molar ratio is 1: (0.005-0.5)), and the water-insoluble iron phosphate and the ferrous oxalate form a specific proportion and can generate a synergistic effect in a solution to accelerate reaction and dissolution; the molar ratio of sodium to iron to phosphorus is accurately controlled to be (4-4.04): (2.9-3): 4, the self-adaption of pH and raw material ratio (the pH is stabilized at 4-6) is synergistically realized by utilizing the characteristics of the raw materials, and the particle refining and dispersing effects of sanding are replaced by combining chemical complexing, step-by-step feeding and multi-parameter coordinated regulation. The process is highly compatible with an existing mass production process, rapid adaptation can be achieved without modifying a production line, the investment and energy consumption of sanding equipment are omitted, the energy consumption of a unit product is reduced by about 20%, and the comprehensive production cost is reduced by 10% or above; the product is pure-phase NFPP, the particle size D50 is 2-10 microns, the first specific discharge capacity is greater than or equal to 105mAh / g, the capacity retention rate after 500 cycles is greater than 95%, and the product is suitable for the fields of energy storage batteries, power batteries and the like and has huge industrial potential.

This invention discloses iron-doped copper hierarchical nanosheets, their preparation, and their application in the electro-oxidation of formaldehyde for hydrogen evolution, relating to the field of hydrogen energy technology. The preparation method of the iron-doped copper hierarchical nanosheets includes the following steps: using a copper mesh as a substrate, in-situ growth of Cu(OH)₂ nanowire arrays is performed by chemical oxidation; the Cu(OH)₂ nanowires undergo ion exchange in an aqueous solution of ferric nitrate to form a hierarchical Fe-Cu(OH)₂ structure. x Nanosheets; Fe-Cu(OH)₂ calcined at high temperature in air atmosphere. x Nanosheets are transformed into Fe-CuO nanosheets; the Fe-CuO nanosheets are then electrochemically reduced to Fe-Cu nanosheets, resulting in an Fe-Cu nanosheet array grown on a copper mesh. The Fe-Cu nanosheet array electrode in this invention exhibits superior formaldehyde electro-oxidation hydrogen evolution performance and significantly broadens the potential window for the electro-oxidation of pure Cu metal formaldehyde, making it suitable for low-energy-consumption electrochemical hydrogen production from formaldehyde.

This invention discloses a method for preparing battery-grade nickel sulfate and iron phosphate using nickel pig iron and ferric phosphate slag as raw materials. The preparation process involves first mixing the ferric phosphate slag with cationic alkyl polyacrylamide to form a uniform mixture. This mixture is then added to dilute acid and stirred to disperse it. Nickel pig iron powder is added, and the mixture is filtered to obtain a leaching solution. The leaching solution is then subjected to nickel-iron separation using resin to obtain an iron-containing solution and a nickel-containing resin. The nickel-containing resin is desorbed to obtain a desorbed solution. A nickel-based pH adjuster is added to this desorbed solution, and the solution is filtered to obtain a nickel sulfate solution. After evaporation and concentration to precipitate crystals, the solution is dried and crushed to obtain battery-grade nickel sulfate. Hydrogen peroxide is added to the iron-containing solution to oxidize ferrous iron to ferric iron. A phosphorus source is added, the pH is adjusted, and the solution is reacted, filtered, and dried to obtain iron phosphate dihydrate. This is then calcined to obtain battery-grade iron phosphate. This invention uses nickel pig iron and ferrophosphate slag as raw materials, and utilizes the ferrophosphate slag to promote the full leaching of iron from nickel pig iron, and nickel pig iron to promote the leaching of phosphate and iron from ferrophosphate. With the addition of cationic alkyl polyacrylamide, it achieves high leaching rates of iron and nickel in a short time, and simultaneously achieves the separation of non-ferrous and nickel metal ions during the acid leaching process, so as to finally obtain high-purity, qualified battery-grade nickel sulfate and ferrophosphate.

The application discloses a treatment method of electroless nickel plating waste liquid, which comprises the following steps: waste liquid pretreatment, waste liquid dephosphorization, waste liquid deironing, waste liquid denickelization, nickel-iron purification and biochemical treatment, and the whole process steps are reasonably designed, the resource treatment of nickel and phosphorus in the waste liquid is realized under the premise of not introducing new pollution factors. By adding an oxidizing agent, high ferric acid is used to remove phosphorus ions, then by adjusting the pH value of the waste liquid, most of the iron ions are precipitated, then modified biochar is used to remove most of the nickel ions, then sulfide precipitant and PAM diluent are added to remove the remaining nickel ions and iron ions, finally, hydrolysis acidification and MBR process are used to quickly remove the remaining complex organic matters, the whole process flow is short, the amount of reagent used is small, and the cost is low.

The application discloses an anti-caking salt product and a preparation method thereof. The anti-caking salt product comprises raw salt and an anti-caking agent, the anti-caking agent is food-grade ferric tartrate, and the addition amount of the anti-caking agent is 0.05-0.106 g / kg of the salt. The core of the anti-caking method of the salt lies in that the food-grade ferric tartrate is used as the main anti-caking agent, the addition amount is 0.05-0.106 g / kg of the salt, the salt is dried at 100 DEG C for 4 hours, then the anti-caking agent is added, and the water vapor transmission rate is less than or equal to 0.5 g / m 2 24h of high-barrier material packaging, while 6 g of quicklime or 2 g of calcium chloride desiccant is added in every 200 g of the salt. The application also controls the Mg 2+ content in the salt to be less than or equal to 0.02%, the KCl content to be less than or equal to 10%, and the particle size to be in the range of 0.45-0.6 mm, so that the salt caking is synergistically inhibited from multiple dimensions. The method has extremely significant anti-caking effect (the caking rate is only 8.7% after 15 days of open storage), is safe and economical, and has a simple process, and can effectively replace or reduce the use of potassium ferrocyanide, and is suitable for large-scale industrial production.

This invention relates to a continuous ferric phosphate reaction and washing system, comprising multi-stage ferric phosphate reaction and washing modules. Each stage of the ferric phosphate reaction and washing module includes a reaction device, an aging device, and a multi-stage membrane washing device connected sequentially along the feed direction. Between adjacent ferric phosphate reaction and washing modules, the multi-stage membrane washing device of the previous stage is connected to the reaction device of the next stage. This invention employs a specially designed reaction device to achieve uniform distribution and continuous reaction of the reaction raw materials, utilizes the aging device to achieve continuous aging of the slurry, and achieves continuous and efficient washing of ferric phosphate powder through the multi-stage membrane washing device. This eliminates the traditional pulping process, reduces washing energy and water consumption, achieves zero loss of phosphoric acid, and improves product quality and stability.

The invention discloses a nickel-vanadium-iron-based self-supporting electrode and a preparation method and application thereof. According to the preparation method, sodium metavanadate and nickel chloride are respectively used as a vanadium source and a nickel source, a sphere-like precursor composed of a sheet structure is synthesized on a foamed nickel substrate through a hydrothermal reaction, anhydrous sodium hypophosphite and ferric nitrate are used as a phosphorus source and an iron source, and the NiO-VO-FeP-coated NF self-supporting electrode is finally formed through phosphating treatment and soaking treatment. According to the electrode obtained by the invention, an adhesive does not need to be added, the preparation process is simplified, the production cost is reduced, the catalytic material is tightly combined with the substrate, the catalyst is prevented from falling off, and the seamless contact provides conditions for rapid transfer of charges, so that the activity of the catalyst is obviously improved. The electrode obtained by the invention has excellent oxygen evolution reaction activity and stability, the oxygen evolution reaction activity of the electrode exceeds that of a commercial RuO2 electrode under high current density, and the electrode shows a good industrial application prospect.

This invention relates to the technical field of ferric phosphate wastewater, specifically to a method and system for treating ferric phosphate wastewater. The treatment method includes the following steps: pretreating ferric phosphate washing wastewater, followed by solid-liquid separation to obtain a first clear liquid and a first precipitate; adding a reducing agent to the first precipitate for dissolution, and adjusting the pH to 1.8-2.0 with acid to obtain a second clear liquid; adjusting the pH of the second clear liquid to 5.2-5.7, and performing solid-liquid separation to obtain a third clear liquid; adjusting the pH of the third clear liquid to 6.8-7.2, and performing solid-liquid separation to obtain a second precipitate; adjusting the pH of the first clear liquid to 8.3-8.5, and performing solid-liquid separation to obtain a third precipitate. This invention, by adjusting the ferric phosphate wastewater to different pH values ​​at different stages, can selectively remove different metal elements under different pH conditions, enabling the classified collection of different metal element precipitates and creating greater economic value.

This invention provides a method for preparing ferric hydroxyphosphate from titanium dioxide byproducts. The method includes: dissolving ferrous sulfate, a byproduct of titanium dioxide production, adding phosphoric acid and iron powder for purification, and filtering to obtain a purified ferrous sulfate solution; adding appropriate amounts of phosphoric acid, hydrogen peroxide, ammonium dihydrogen phosphate solution, and ammonia to the ferrous sulfate solution and reacting for a period of time to form a mixed slurry; repeatedly washing and filtering the mixed slurry to form a ferric hydroxyphosphate precursor; flash drying, sintering, pulverizing, mixing, and then packaging the ferric hydroxyphosphate product. According to this invention, the method for preparing ferric hydroxyphosphate from titanium dioxide byproducts yields a ferric hydroxyphosphate product with advantages such as low cost, low impurity content, and excellent performance. Furthermore, this method has low equipment requirements, a simple process flow, and improves production efficiency, making it suitable for large-scale industrial production.

The application relates to the technical field of inorganic compound preparation, and particularly discloses a method for preparing high-purity iron phosphate from phosphating slag by low-temperature acidolysis, which comprises the following steps: washing, drying and smashing the phosphating slag to obtain phosphating slag powder; performing low-temperature acidolysis reaction on the phosphating slag powder and inorganic acid in an aqueous medium at 60-90 DEG C to obtain an acidolysis solution; adding an oxidizing agent to the acidolysis solution and adjusting the pH value of the system to 2.5-4.5 at 65-85 DEG C to remove impurities by oxidation, and then filtering to obtain an iron phosphate solution; selectively supplementing an iron source according to the molar ratio of iron to phosphorus in the solution, adjusting the pH value to 1.0-3.0, and performing a precipitation reaction at 65-75 DEG C to generate iron phosphate. The application realizes low-energy-consumption resource utilization of the phosphating slag by combining low-temperature acidolysis with oxidation impurity removal and component regulation, the purity of the product reaches the battery grade requirement, and the product is suitable for preparation of a lithium battery positive electrode material precursor.